CVE-2026-19820

7.8 highEPSS 0.5%

High (7.8). EPSS 0.5% chance of exploitation in the next 30 days.

A vulnerability in the Backblaze Client allows a local user to make the system not bootable by creating a link from Backblaze's folder to Windows OS system files during a backup. Successful exploitation requires an administrator-level system change that results in the absence of specific Windows OS security controls. This vulnerability is due to improper link resolution.

Severity

CVSS 4.0

7.8 high

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:L

EPSS: 0.5% chance of exploitation in the next 30 days; higher than 42% of CVEs (scores of 2026-10-31)
CWE: CWE-59
Published: 2026-09-01
Modified: 2026-09-11
Record from: the NVD, synced 2026-10-19

References

https://www.backblaze.com/computer-backup/docs/backup-client-release-notes-windows
https://www.backblaze.com/status/update

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